In recent years, semiconductor light-emitting elements have been reduced in thickness and rigidity with increasing luminance and efficiency. Further, flip-chip mounting has been adopted as a technique for mounting bare chips of semiconductor light-emitting elements on mounting boards. The flip-chip mounting is a technique for forming a metal electrode on the electrode portion of a semiconductor light-emitting element to electrically join the metal electrode on the semiconductor light-emitting element to a metal electrode on a mounting board.
The process of flip-chip mounting is complicated, so that the joining surface cannot be directly observed. Thus, Patent Literature 1 proposes a technique for bringing a probe needle into direct contact with a semiconductor light-emitting element before flip-chip mounting to evaluate the optical properties and electrical properties of the semiconductor light-emitting element.
Further, Patent Literature 2 proposes a technique for performing evaluations on a semiconductor element and a mounting board after flip-chip mounting using X-ray equipment or an infrared microscope. The inspection device is configured as shown in FIG. 10.
In FIG. 10, X-rays irradiated from an X-ray generator 100 pass through a flip chip 103 and a circuit board 102, and an X-ray sensor 104 converts the rays to light with the sensor surface to obtain images. The flip chip 103 is flip-chip joined onto the circuit board 102. For the flip-chip joining portion, a heavy metal material such as lead and gold having high X-ray absorption is used. Thus, the flip-chip joining portion is darker than the surrounding in an X-ray image, so that the position of the joining portion can be easily specified. A position level with the underside of the flip chip 103 corresponding to the upper part of the joining portion is measured by a laser focus displacement meter 105. The laser focus displacement meter 105 can measure the position from the side via a mirror 106 allowing the passage of X-rays without affecting the X-ray photography.
Patent Literature 3 describes a die bonding method in which, in the assembly of an optical head, a light-emitting element is electrified to correct a displacement of the light-emitting element.
Patent Literature 4 describes a technique for retaining a light-emitting element by suction before mounting and electrifying the retained light-emitting element to measure the luminance and select the light-emitting element.
Patent Literature 5 describes a technique for mounting a semiconductor element suctioned and retained by a bonding tool on a printed circuit board while detecting the pressing force with the bonding tool.